A silver halide photographic material comprises at lease one silver halide emulsion layer and at least one non-light-sensitive hydrophilic colloidal layer provided on a support. The silver halide emulsion layer or the hydrophilic colloidal layer often contains a dye, which absorbs a light of a specific wavelength. The dye has a function of controlling spectrum of light incident on the emulsion layer, adjusting light absorption (in a filter layer), preventing halation or irradiation or adjusting the sensitivity of the emulsion layer.
The dye used in a photographic material must satisfy the following conditions:
(1) The dyes have a spectral absorption suitable for their use.
(2) The dyes are inactive chemical compounds in photographic reactions. For example, the dyes should not have adverse chemical effects on silver halide emulsion layers. The adverse effects include reduction of sensitivity, regression of latent image and fog. Further, the dyes should be inactive with a coupler or a developing agent.
(3) The dyes are bleached or dissolved in a processing solution or a washing water. The dyes should not remain in the processed photographic material.
(4) The dyes are stable in a solution or in a photographic material. The color of the dyes should not be faded nor discolored.
A cyan dye has recently been used in a silver halide photographic material to improve the sharpness of a red sensitive emulsion layer. In this case, the condition (1) is particularly necessary. The cyan dye must have an absorption maximum of a spectrum in the range of 680 to 720 nm to improve the red sensitive layer effectively without decreasing the sensitivities of blue and green sensitive layers.
Therefore, various cyan dyes have been searched and developed to satisfy the above-mentioned conditions. Some pyrazolone-pentamethine oxonol dyes satisfy most of the conditions. Japanese Patent Publication No. 51(1976)-46607 discloses pyrazolone-pentamethine oxonol dyes, wherein an alkoxycarbonyl group is attached to the 3-position of pyrazolone. Japanese Patent Publication No. 60(1985)-53304 discloses pyrazolone-pentamethine oxonol dyes, wherein cyano is attached to the 3-position of pyrazolone. Japanese Patent Provisional Publication No. 62(1987)-273527 discloses pyrazolone-pentamethine oxonol dyes, wherein an acyl group is attached to the 3-position of pyrazolone. Japanese Patent Provisional Publications No. 58(1983)-143342, No. 2(1990)-97940 and Japanese Patent Publication No. 3(1991)-40371 disclose pyrazolone-pentamethine oxonol dyes, wherein a carbamoyl group is attached to the 3-position of pyrazolone. Particularly, Japanese Patent Publication No. 2(1990)-97940 (corresponding to U.S. Pat. No. 4,996,138, Murai et al.) discloses various (103) examples of the pyrazolone-pentamethine oxonol dyes.
However, the disclosed dyes do not completely satisfy the conditions. Some dyes do not satisfy the condition (1), namely they do not have an absorption maximum of a spectrum in the range of 680 to 720 nm. Other dyes do not satisfy the condition (3), namely it is difficult to bleach or dissolve them in a processing solution or a washing water. The other dyes do not satisfy the condition (4), namely they are not stable in a coating solution before coating or in a photographic material after coating.